1. Field of the Invention
This invention relates to a stereoscopic image display device, and more particularly to a stereoscopic image display device that is adaptive for displaying a stereoscopic image without a deterioration of resolution.
2. Description of the Related Art
Generally, a stereoscopic image display device takes advantage of the perspective represented when different image signals recognized by two eye of an observer are combined to display an image stereoscopically. Such a stereoscopic image display device is largely classified into an auto-stereoscopic system and a binocular system. The former permits an appreciation of stereoscopic image with no auxiliary equipment, whereas the latter requires auxiliary equipment such as a polarization glass for the purpose of appreciating a stereoscopic image. Accordingly, nowadays, there have actively conducted a study and development of the stereoscopic image display device of auto-stereoscopic system.
FIG. 1 shows a stereoscopic image display device disclosed in Korean Patent Application No. 98-55228 filed on Dec. 16, 1998 by LG Electronics Inc. The stereoscopic image display device includes first and second cameras 2a and 2b for photographing an object at a different angle, an image signal converter 4 for converting an image signal applied from the first and second cameras 2a and 2b into a specific shape, a display 6 for displaying a picture corresponding to the converted image signal, and a color barrier 8 arranged between the display, 6 and an observer to choose color signals. An image signal photographed with the first camera 2a includes red(r1), green(g1) and blue(b1) color signals while an image signal photographed with the second camera 2b includes red(r2), green(g2) and blue(b2) different from the image signal photographed with the first camera 2a. In the display 6, a first picture element (or pixel) P1 displayed by r1, g2 and b2 color signals and a second picture element P2 displayed by r2, g1 and b1 color signals are alternately arranged. In the color barrier 8, a red filter 8R and a cyan filter 8C that have the color selectivity of complementary color relationship, are alternately arranged. The red filter 8R transmits only a red light while the cyan filter 8C transmits a green or blue light. When an observer views an image signal via the color barrier 8, an image signal having r1, g1 and b1 color signals is incident to the left eye of an observer while an image signal having r2, g2 and b2 color signals is incident to the right eye of an observer. Accordingly, an object photographed with the first camera 2a emerges at the left eye of an observer, whereas an object photographed with the second camera 2b emerges at the right eye of an observer. Since image signals at a different angle are viewed by the left and right eyes of an observer and then combined in the above manner, an observer can view a stereoscopic image.
Such a stereoscopic image display device divides the displayed image signal into two signals to display a two-view three-dimension (3D) image. The stereoscopic image display device as shown in FIG. 1, however, has a disadvantage in that its resolution is deteriorated in inverse proportion to the number of views. In the case of the two-view 3D image as shown in FIG. 1, the resolution is reduced to xc2xd because two cells of the red filter 8R and the cyan filter 8C is required to display a single of image signal. In other words, if the stereoscopic image display device as shown in FIG. 1 is to display an n-view 3D stereoscopic image, then its resolution is reduced to 1/n.
Alternatively, a stereoscopic image may be perceived without a deterioration of resolution by taking advantage of a blinking-type light source. Referring to FIG. 2, a two-view 3D stereoscopic display device employing such a blinking-type light source includes a blinking light source 12, and a display 14 on which an image is displayed. In the blinking light source 12, a first light source L1 and a second light source L2 are alternately arranged. The first and second light sources L1 and L2 are opposed to pixel cells of the display 14. These first and second light sources L1 and L2 are alternately turned on and off to emit a light to the pixel cells of the display 14. In a t1 interval, the first light source L1 is turned on while the second light source L2 is turned off. At this time, an observer views a picture as shown in FIG. 3A. Specifically, if the first light source only is turned on, then the left eye of an observer can perceive only a first pixel cell 14a, and the light eye of an observer can perceive only a second pixel cell 14b. Subsequently in a t2 interval, the first light source L1 is turned off while the second light source L2 is turned on. Then, an observer can view only the second pixel cell 14b with his left eye and only the first pixel cell 14a with his right eye as shown in FIG. 3B. As described above, the stereoscopic image display device employing the blinking light source changes an image signal with the lapse of time, so that it can display a stereoscopic image without a deterioration of resolution. In other words, in the case of a two-view 3D stereoscopic image, the stereoscopic image display device displays two image signals via two pixel cells in the t1 and t2 intervals to prevent a deterioration of resolution.
Accordingly, it is an object of the present invention to provide a, stereoscopic image display apparatus that is capable of displaying a stereoscopic image without a deterioration of resolution.
In order to achieve these and other objects of the invention, a stereoscopic image display apparatus according to an embodiment of the present invention includes display means for displaying an image; and color converting means for differentiating a wavelength range of a light transmitted at a desired time interval with respect to a certain pixel area in the display means.
A stereoscopic image display apparatus according to another embodiment of the present invention includes display means for displaying an image; and color converting means, having a light transmitting area and a light shutting-off area for each pixel cell of the display means, for alternating the light transmitting area and the light shutting-off area at a desired time interval with respect to a certain pixel area of the display means.
A stereoscopic image display apparatus according to still another embodiment of the present invention includes display means for displaying an image; color signal generating means for generating a different wavelength of lights for each pixel cell of the display means; and optical shutter means, having a light transmitting area and a light shutting-off area for each pixel cell of the display means, for differentiating the light transmitting area and the light shutting-off area at a desired time interval with respect to a certain pixel area of the display means.
A stereoscopic image display apparatus according to still another embodiment of the present invention includes display means for displaying an image; color converting means for differentiating a wavelength range of lights at a desired time interval with respect to a certain pixel area of the display means; and light shutter means having a light transmitting area and a light shutting-off area for each pixel cell of the display means.